Support for the following eight research projects is sought: A. Electron Deficient Analogs of FMN and FAD as Traps for Covalent Intermediates in Flavoenzyme Catalyzed Redox Reactions. B. The Question of Hydride Transfer from Dihydropyridine Nucleotides in Flavoenzymes (Use of 5-Deazaflavin Analogs of FMN and FAD). C. Chemistry of Arene Oxides Related to Carcinogenesis, Liver Necrosis, and Drug Metabolism. D. Arene Oxides as Active Site Agents for -SH Enzymes. E. A Model for Glycosidases and Acid Peptidases. A Study of Rennin. F. Prochiral Recognition and Stereospecific Catalysis. G. The Synthesis, Physical, and Chemical Properties of Encapsulated Tetra(mercapto-micron 3-sulfido- iron) Clusters. Ferrodoxins. H. Catalysis of Acyl Transfer Reactions. (1) Synthetic Charge-Relay Systems for Serine Esterases. (2) Acyl Transfer Reactions from Stable Tetrahedral Intermediates. (3) Metal Ion Catalysis of Aliphatic Ester and Amide Hydrolysis in an Intramolecular Model.